
.container {
    position: relative;
    height: 100px;
    display: flex;
    justify-content: space-between;
    width: 450px;
    align-items: center;
    background-color: #181818;
}

.container::before {
    position: absolute;
    content: "";
    left: 0;
    width: 200px;
    height: 100%;
    background: linear-gradient(to left, transparent, #181818); // 与元素的背景色保持一致
}
.container::after {
    position: absolute;
    content: "";
    right: 0;
    width: 200px;
    height: 100%;
    background: linear-gradient(to right, transparent, #181818); // 与元素的背景色保持一致
}

.item {
    width: 60px;
    height: 60px;
    background-color: aquamarine;
}